JP3837786B2

JP3837786B2 - Electromagnetic clutch

Info

Publication number: JP3837786B2
Application number: JP24218296A
Authority: JP
Inventors: 泰生田渕; 昌史鳥羽山
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1996-09-12
Filing date: 1996-09-12
Publication date: 2006-10-25
Anticipated expiration: 2016-09-12
Also published as: DE19740236B4; DE19740236A1; US5941357A; JPH1089385A

Description

【０００１】
【発明の属する技術分野】
本発明は動力伝達を断続する電磁クラッチに関するもので、自動車用空調装置の冷凍サイクルの圧縮機駆動用として好適なものである。
【０００２】
【従来の技術】
従来、自動車用空調装置の冷凍サイクルの圧縮機は、電磁クラッチを介してエンジンに連結され、電磁クラッチによりエンジンからの動力伝達が断続されるようになっている。
ところで、圧縮機が焼きつき等の故障を発生して、その回転軸がロックすると、エンジンの動力伝達装置のベルトに過大な力が加わり、このベルトの破損等の不具合が生じる。このベルト破損等の不具合が一旦生じると、エンジン冷却水循環用ウォータポンプ、バッテリ充電用発電機等のエンジン補機が作動不能となり、エンジンの運転停止という重大事態を引き起こすので、この不具合を未然に防止するための対策が必要である。
【０００３】
そこで、従来では、以下のような対策を一般に講じている。すなわち、エンジン側からの動力を受けて回転している入力側のロータと、この入力側ロータに、電磁コイルの電磁吸引力により吸着されて回転する出力側のアーマチャとを有する電磁クラッチにおいて、圧縮機のロック時には出力側のアーマチャが回転不能となり、このアーマチャに対して前記ロータが滑りながら回転するので、この滑り接触部分の温度が異常上昇する。
【０００４】
そこで、このアーマチャとロータとの滑り接触部分における温度の異常上昇に注目して、この温度の異常上昇により溶断する温度ヒューズを設置し、この温度ヒューズの溶断により前記電磁コイルへの通電を遮断して、電磁クラッチを動力遮断状態とすることにより、上記ベルトに過大な力が加わるのを防止している。このような温度ヒューズを設置した従来技術としては、特開昭５７−５１０２５号公報に記載されたものがあり、この従来技術では、前記電磁コイルを保持するコイルスプール（巻枠）を、コイルハウジング（固定磁極部材）内に固定するとともに、コイルスプールのうち、ロータ端面に対向する部位に温度ヒューズを設置している。
【０００５】
【発明が解決しようとする課題】
しかしながら、上記従来技術においては、温度ヒューズの設置場所を、具体的には、コイルスプールの半径方向に延びる側面のうち、内周部と外周部との間の略中間部位に設定しているので、この温度ヒューズの設置スペース分だけ、コイルスプールの軸長が縮小してしまい、その結果、コイルスプールに保持される電磁コイルの巻数が減少するので、所要の電磁吸引力を確保するために、電磁コイルの消費電力が増大するという問題がある。
【０００６】
また、本発明者らの実験、検討によると、上記従来技術では、次のごとき問題も生じることが分かった。
すなわち、温度ヒューズが、コイルハウジングより離れた部位において、電磁コイルおよびコイルスプールを絶縁固定する樹脂部材により覆われて設置されているので、温度ヒューズ周辺部の熱は外部に放出されにくい。
【０００７】
そのため、圧縮機正常時に電磁コイルが通電され、発熱すると、この発熱の影響を受けて温度ヒューズ周辺部も温度上昇して、温度ヒューズの溶断温度以上に上昇する場合が生じ、これにより正常時にもかかわらず、温度ヒューズが溶断するという誤作動が生じることがある。
また、圧縮機のロック時にはアーマチャとロータとの滑り接触部分における温度上昇の伝達が上記樹脂部材により妨げられて、滑り接触部分の熱が温度ヒューズに伝わりにくいので、温度ヒューズが溶断するまでの時間が長くかかり、応答性が悪いという問題が生じる。この応答性の悪化により、温度ヒューズの溶断前に、電磁クラッチの軸受（ボールベアリング）が温度上昇してロックしてしまう場合がある。
【０００８】
本発明は上記点に鑑みてなされたもので、第１には、温度ヒューズの設置に伴う電磁コイルの巻線スペースの減少を抑制することを目的とする。
第２には、正常時における温度ヒューズの誤作動の可能性を低減できるとともに、クラッチ滑り時における温度ヒューズ溶断の応答性を向上できる電磁クラッチを提供することを目的とする。
【０００９】
【課題を解決するための手段】
本発明は上記目的を達成するため、以下の技術的手段を採用する。請求項１〜９記載の発明では、回転駆動源からの回転力を受けて回転する駆動側回転部材（１、２）と、従動側機器の回転軸に連結される従動側回転部材（１２）と、通電により電磁吸引力を発生する電磁コイル（５）と、この電磁コイル（５）を収納し、固定するコイルハウジング（４）と、電磁コイル（５）の発生する電磁吸引力により駆動側回転部材（１、２）の摩擦面（２ａ）に吸着されるアーマチャ（８）と、従動側回転部材（１２）とアーマチャ（８）との間を弾性的に連結する弾性連結機構（９、１０、１１）とを備え、さらに、コイルハウジング（４）内において、駆動側回転部材（１、２）の摩擦面（２ａ）に近接した部位に温度ヒューズ（１３）を配設し、この温度ヒューズ（１３）を、所定温度以上において溶断して、電磁コイル（５）への通電を遮断するようにした電磁クラッチにおいて、コイルハウジング（４）内に円環状のコイルスプール（１４）を配設して、このコイルスプール（１４）上に電磁コイル（５）を巻線するとともに、このコイルスプール（１４）のうち、駆動側回転部材（１、２）の摩擦面（２ａ）側に位置する内周角部に、凹所（１４ｂ）を形成し、この凹所（１４ｂ）に温度ヒューズ（１３）を配設することを特徴としている。
更に、請求項１記載の発明では、上記に加えて、コイルスプール（１４）内において凹所（１４ｂ）の外周側領域にも電磁コイル（５）を巻線している。
【００１０】
この構成によると、コイルスプール（１４）の内周角部に形成した凹所（１４ｂ）に温度ヒューズ（１３）を配設しているので、従来技術のように、コイルスプールの半径方向に延びる側面のうち、内周部と外周部との間の略中間部位に温度ヒューズ（１３）を配設する場合のように、温度ヒューズの設置に伴って、コイルスプール全体の軸長が縮小することがなく、コイルスプール（１４）の内周角部のみが局所的にスペースを減少するだけですむ。
【００１１】
その結果、コイルスプール（１４）に保持される電磁コイルの巻数の減少を従来技術よりも大幅に抑制でき、所要の電磁吸引力を確保するための、電磁コイルの消費電力増大を僅少値に抑制できるという効果が大である。
しかも、上記に加えて、温度ヒューズの誤作動の低減および応答性の向上をも達成できる。すなわち、圧縮機等の従動側機器の正常作動時に、電磁コイル（５）が通電により発熱しても、温度ヒューズ（１３）がコイルスプール（１４）の内周角部に位置し、コイルハウジング（４）の壁面に近接しているので、温度ヒューズ周囲の熱は、樹脂よりも熱伝導性が良好な、磁性体金属からなるコイルハウジング（４）側に放熱されるので、温度ヒューズ周囲の温度は、熱伝導度が低い樹脂部材の中央部内に位置している場合に比してかなり低い温度となる。
【００１２】
そのため、電磁コイル（５）が発熱しても、その発熱の影響を受けて、温度ヒューズ（１３）が誤作動し、溶断する可能性を著しく低減できる。
一方、従動側機器が焼きつき等の重大故障を起こしてロックすると、アーマチャ（８）と駆動側回転部材（１、２）との滑り接触部分が摩擦熱により異常に温度上昇する。このとき、コイルハウジング（４）は樹脂よりも熱伝導度が高いので、コイルハウジング（４）のうち、駆動側回転部材（１、２）の摩擦面（２ａ）に近接した端部は駆動側回転部材（１、２）の温度上昇による熱を受けて速やかに温度上昇する。そして、温度ヒューズ（１３）は、上記コイルハウジング（４）の端部を通して受熱するため、駆動側回転部材（１、２）の温度上昇に対して応答よく温度上昇する。
【００１３】
これにより、従動側機器のロック発生後、短時間で温度ヒューズ（１３）がその溶断温度まで上昇して溶断し、電磁コイル（５）への通電を遮断できる。従って、温度ヒューズ（１３）の溶断前に、電磁クラッチの軸受が温度上昇してロックしてしまうといった不具合を確実に阻止できる。
請求項２記載の発明では、コイルスプール（１４）のうち、駆動側回転部材（１、２）の摩擦面（２ａ）側に位置する内周角部に、駆動側回転部材（１、２）の摩擦面（２ａ）から離れる方向に傾斜した傾斜面（１４ａ）を形成し、この傾斜面（１４ａ）により凹所（１４ｂ）が形成されており、この凹所（１４ｂ）に温度ヒューズ（１３）を配設することを特徴としている。
請求項３記載の発明では、コイルスプール（１４）のうち、駆動側回転部材（１、２）の摩擦面（２ａ）側に位置する内周角部に、駆動側回転部材（１、２）の摩擦面（２ａ）から離れる方向に凹む段付部（１４ｋ）を形成し、この段付部（１４ｋ）により凹所（１４ｂ）が形成されており、この凹所（１４ｂ）に温度ヒューズ（１３）を配設することを特徴としている。
請求項４記載の発明では、コイルスプール（１４）のうち、駆動側回転部材（１、２）の摩擦面（２ａ）側に位置する内周角部に、駆動側回転部材（１、２）の摩擦面（２ａ）から離れる方向に傾斜した傾斜面（１４ｂ）と、駆動側回転部材（１、２）の摩擦面（２ａ）から離れる方向に凹む段付部（１４ｋ）とを形成し、この傾斜面（１４ａ）および段付部（１４ｋ）により凹所（１４ｂ）が形成されており、この凹所（１４ｂ）に温度ヒューズ（１３）を配設することを特徴としている。
請求項５記載の発明では、コイルスプール（１４）のうち、駆動側回転部材（１、２）の摩擦面（２ａ）側に位置する内周角部に、凹所（１４ｂ）を形成し、この凹所（１４ｂ）に温度ヒューズ（１３）を配設し、
更に、コイルハウジング（４）は、断面コの字形状の２重円筒形状に形成されており、コイルハウジング（４）の２重円筒形状のうち、内周側円筒部（４ａ）の摩擦面（２ａ）側先端部に、外周面から内周面側へ傾斜する傾斜面（４ｃ）を形成し、この傾斜面（４ｃ）に沿うように凹所（１４ｂ）を形成することを特徴としている。
【００１４】
この構成によると、コイルハウジング（４）の内周側円筒部（４ａ）の先端部傾斜面（４ｃ）に沿って凹所（１４ｂ）を形成することにより、傾斜面（４ｃ）を利用して凹所（１４ｂ）を拡大でき、電磁コイル（５）の巻数減少をより一層効果的に抑制できる。
請求項６記載の発明では、請求項２ないし５のいずれか１つに記載の電磁クラッチにおいて、コイルスプール（１４）内において凹所（１４ｂ）の外周側領域にも電磁コイル（５）が巻線されていることを特徴とする。
請求項７記載の発明では、請求項１ないし６のいずれか１つに記載の電磁クラッチにおいて、コイルスプール（１４）は、弾性を有する樹脂にて成形されており、
前記内周角部に前記温度ヒューズ（１３）を弾性的に保持する爪片（１４ｃ、１４ｄ）が一体成形されていることを特徴とする。
請求項８記載の発明では、請求項１ないし７のいずれか１つに記載の電磁クラッチにおいて、コイルスプール（１４）は、温度ヒューズ（１３）の両端側近傍に、電磁コイル（５）を取り出すための切欠き部（１４ｇ）を有し、
この切欠き部（１４ｇ）から取り出された電磁コイル（５）を切断して、温度ヒューズ（１３）の両端に電気接続したことを特徴とする。
請求項９記載の発明では、請求項１ないし８のいずれか１つに記載の電磁クラッチにおいて、コイルスプール（１４）および温度ヒューズ（１３）は、コイルハウジング（４）内に成形された樹脂部材（６）により固定保持されていることを特徴とする。
なお、上記各手段の括弧内の符号は、後述する実施形態記載の具体的手段との対応関係を示すものである。
【００１５】
【発明の実施の形態】
以下、本発明を図に示す実施形態について説明する。
（第１実施形態）
図１および図２において、１は駆動側プーリで、図示しないベルトを介して自動車エンジンから回転力を受けて回転するものである。このプーリ１は多重Ｖベルトが係合される多重Ｖ溝を持ったプーリ部１ａが一体形成されており、鉄系金属で製作されている。
【００１６】
２は断面コの字形状の２重円筒形状に形成された駆動側ロータで、鉄系金属（強磁性体）で製作されており、プーリ１とは溶接等の接合手段で一体に接合されている。このロータ２の内周部には、ベアリング３が配置され、このベアリング３によりロータ２は図示しない圧縮機のフロントハウジングの円筒突出部上に回転自在に支持されるようになっている。ここで、圧縮機は自動車用空調装置の冷凍サイクルの冷媒圧縮用のものである。
【００１７】
４は固定磁極部材としての役割を果たすコイルハウジングで、内周側円筒部４ａおよび外周側円筒部４ｂを有する、断面コの字形状の２重円筒形状に鉄系金属（強磁性体）で形成されている。このコイルハウジング４の内周側円筒部４ａ上に位置するようにして、円環状の樹脂製コイルスプール１４がコイルハウジング４の内部に配設されている。このコイルスプール１４上に電磁コイル５が巻線され、保持固定されている。そして、このコイルスプール１４と電磁コイル５は樹脂部材６によりコイルハウジング４内に絶縁固定されている。
【００１８】
ここで、樹脂部材６は、本例では、エポキシ樹脂、不飽和ポリエステルのような比較的低温（１３０〜１４０°Ｃ）で成形できる樹脂材料をコイルハウジング４の内部空間に注入し成形したものである。また、コイルスプール１４を構成する樹脂材料としては、電磁コイル５の発熱に耐える耐熱性に優れ、かつある程度の剛性を有する樹脂が好ましく、例えばナイロン、ポリフェニレンサルファイド、ポリブチレンテレフタレート等を用いる。これらの樹脂の熱変形温度は、樹脂部材６の成形温度（１３０〜１４０°Ｃ）より十分高い温度（２００°Ｃ以上）であるので、樹脂部材６の成形による不具合は発生しない。
【００１９】
一方、コイルハウジング４はロータ２の断面コの字形状の内部空間内に微小隙間を介して配設されており、これによりロータ２はコイルハウジング４に対して回転自在になっている。このコイルハウジング４の背面部には鉄系金属で略四角形状に形成されたステー７が点溶接等により接合されている。このステー７の中心部には、圧縮機のフロントハウジングの円筒突出部（図示せず）が貫通する円形穴７ａが開けられている。
【００２０】
このステー７を介してコイルハウジング４は圧縮機のフロントハウジングに固定されるようになっている。
ロータ２の半径方向に延びる摩擦面２ａには、銅（非磁性体）からなるリング状の磁気遮断部材２ｂ、２ｃが配設してある。さらに、磁気遮断部材２ｂの部位には摩擦材２ｄが配設され、伝達トルクの向上を図るようにしてある。
【００２１】
８はロータ２の摩擦面２ａに対向して配設されたアーマチャで、リング状に鉄系金属（強磁性体）で形成されている。このアーマチャ８は電磁コイル５の非通電時には後述するゴム製弾性部材９の弾性力によりロータ２の摩擦面２ａから所定の微小距離離れた位置に保持されるようになっている。このアーマチャ８には、円周方向に延びる円弧状の磁気遮断溝８ａが形成されている。
【００２２】
電磁コイル５への通電により発生する磁束が流れる磁気回路（図１の一点鎖線Ｘ参照）は、上記ロータ２、コイルハウジング４およびアーマチャ８により構成されている。
１０は鉄系金属からなるリベットで、アーマチャ８をゴム製弾性部材９を介して保持部材１１に連結するものである。この連結構造を具体的に説明すると、リベット１０は図２に示すように１２０度間隔で３本配設され、その頭部１０ａにてアーマチャ８に一体にかしめ固定されている。そして、リベット１０の軸部１０ｂの外周面に円筒状のゴム製弾性部材９が一体に接着固定されており、弾性部材９の外周面は保持部材１１の円筒状保持部１１ａの内周面に圧入固定されている。
【００２３】
保持部材１１は鉄系金属にて形成されたもので、上記円筒状保持部１１ａを頂部付近に一体形成した略正三角形の形状である。また、保持部材１１はその中心部に円形の穴１１ｂを有し、この円形の穴１１ｂの周縁部に、ハブ１２が３本のリベット１２ａによりかしめ固定されている。このハブ１２は鉄系金属にて形成されており、その中心円筒部１２ｂの内周には、圧縮機の回転軸（図示せず）がスプライン結合等により回り止め嵌合され、そしてハブ１２と圧縮機の回転軸は図示しないボルトにより一体に締めつけ固定されるようにしてある。
【００２４】
また、弾性部材９の材質としては、自動車の使用環境温度範囲（−３０°Ｃ〜１１５°Ｃ）に対して、トルク伝達およびトルク変動吸収の面で優れた特性を発揮するゴムを用いることが好ましく、具体的には、塩素化ブチルゴム、アクリロニトリルブタジエンゴム、エチレンプロピレンゴム等のゴムがよい。
なお、本例では、プーリ１とロータ２により駆動側回転部材を構成し、ハブ１２により従動側回転部材を構成している。そして、弾性部材９、リベット１０および保持部材１１により、ハブ（従動側回転部材）１２とアーマチャ８との間を連結する弾性連結機構を構成し、電磁コイル５の非通電時には弾性部材９の弾性力によりアーマチャ８をロータ２の摩擦面２ａから開離した位置に保持するようにしてある。
【００２５】
１３は温度ヒューズで、所定温度（本例では１８４°Ｃ）において溶融する感温部材（有機化合物からなる樹脂製部材）を内蔵し、この感温部材が溶融するまでは接点間の電気的接続状態を維持し、そして感温部材が溶融すると、スプリングの作用で接点間を切り離して、電気的接続状態を遮断する構成である。
この温度ヒューズ１３はこれらの感温部材、接点機構、スプリング等を円筒状ケース内に収納した略円柱状の形状に形成されている。そして、この温度ヒューズ１３は圧縮機ロック時にアーマチャ８が回転不能となり、このアーマチャ８に対してロータ２が滑りながら回転することにより、この滑り接触部分の温度が異常上昇するのを感知して遮断状態になるものである。
【００２６】
従って、温度ヒューズ１３は圧縮機ロック時におけるアーマチャ８とロータ２との滑り接触に基づく温度の異常上昇を応答よく感知する必要があり、しかも圧縮機正常時における電磁コイル５の発熱に対しては誤作動しないようにする必要がある。
上記点を考慮して、本実施形態では、温度ヒューズ１３の配置場所を次のように設定している。図４〜図６はコイルスプール１４単体の形状を示し、図７（ａ）および図８〜図１０は温度ヒューズ１３の配設場所の拡大図である。これらの図に基づいて、温度ヒューズ１３の配設部の構成を具体的に説明すると、コイルスプール１４のうち、ロータ２の摩擦面２ａ側に位置する内周角部に、摩擦面２ａから離れる方向に傾斜した傾斜面１４ａを全周にわたって形成してある。
【００２７】
この傾斜面１４ａによりコイルスプール１４の内周角部に凹所１４ｂを形成し、この凹所１４ｂ内を温度ヒューズ１３の配設場所として構成している。
ここで、傾斜面１４ａの外側は全周にわたって、連続して傾斜しておらず、傾斜面１４ａの外側面は所定間隔毎に傾斜が遮断されている。この外側面の傾斜遮断部位は補強用リブ１４ｅを形成している。
【００２８】
なお、コイルハウジング４の内周側円筒部４ａの先端部には、外周面から内周面に向かって傾斜する（断面積を小さくする）傾斜面４ｃ（図７（ａ）参照）が形成してある。この傾斜面４ｃは、図１の磁気回路Ｘにおいて、磁束がロータ２の摩擦面２ａの半径方向中間部へ直接向かうのを防止して、磁束がロータ２の内周円筒部側へ向かうようにするためのものである。
【００２９】
この傾斜面４ｃにより凹所１４ｂが拡大され、温度ヒューズ１３の配設面積を拡大することができる。
図７（ａ）および図８〜図１０に拡大図示するように、コイルスプール１４の内周角部の傾斜面１４ａには、温度ヒューズ１３を弾性的に保持する２つの爪片１４ｃ、１４ｄが一体成形されている。ここで、一方の爪片１４ｃは、コイルハウジング４の内周側円筒部４ａの先端部傾斜面４ｃに沿って、コイルスプール１４の内周方向へ斜めに延びるように成形してあり、これにより、電磁コイル５の巻線スペースの減少を抑制しながら、温度ヒューズ１３の配設面積を確保しやすくしている。
【００３０】
また、２つの爪片１４ｃ、１４ｄの間隔は、温度ヒューズ１３の円筒形状の外径より所定量小さく設定して、温度ヒューズ１３に弾性的な保持力が作用するようにしてある。
また、傾斜面１４ａの外側面のうち、温度ヒューズ１３の配設部位は温度ヒューズ１３の外周面に沿った円弧状保持面１４ｆを形成している。
【００３１】
さらに、コイルスプール１４の内周角部は、温度ヒューズ１３の両端側近傍に、電磁コイル５の一部を取り出すための切欠き部１４ｇを形成し、この切欠き部１４ｇから取り出された電磁コイル５の一部のコイル線５ａを切断し、この切断したコイル線５ａに温度ヒューズ１３の両端のリード線１３ａを結線部５ｂにて電気接続するようにしてある。ここで、結線部５ｂによるコイル線５ａとリード線１３ａとの電気的および機械的接合は、半田付け、ヒュージング、かしめ等の手段で行うことができ、図示の例では、適宜の金属クランプをかしめる例を示している。
【００３２】
そして、電磁コイル５のコイル線５ａと温度ヒューズ１３のリード線１３ａが配設される範囲では、コイルスプール１４の内周角部にその内周側へ斜めに突出する突出片１４ｈを形成し、この突出片１４ｈにより、コイルスプール１４内に巻線された電磁コイル５部分と、上記コイル線５ａおよびリード線１３ａとの電気絶縁を確実に行うようにしてある。
【００３３】
一方、コイルスプール１４に電磁コイル５の巻始め側端部および巻終わり側端部を取り出すためのコイル取り出し部１４ｉが一体に成形されている。このコイル取り出し部１４ｉは、コイルスプール１４において、ロータ２の摩擦面２ａとは反対側の部位で、かつ温度ヒューズ１３の配設部位とは円周方向で１８０°対称の部位に配置され、電磁コイル５の両端部取り出し用の穴１４ｊを２個有している。
【００３４】
電磁コイル５の両端部５ｃ、５ｄ（図１１参照）は、コイルハウジング４の内外両円筒部４ａ、４ｂの中間の側面部に開けられた穴（図示せず）を通してコイルハウジング４の外部に取り出され、コネクタ１５内の電気端子１５ａ（図１１参照）に電気接続されるようになっている。図１１は電磁クラッチの組付完了後の電気結線状態を示す。
【００３５】
なお、図１においてコイルハウジング４のＡ部は、断面図示の煩雑化を避けるため、断面図示を省略しており、このＡ部に上記穴が設けられている。
ところで、温度ヒューズ１３は、図１から理解されるように、コイルハウジング４の内周側円筒部４ａの外周壁面に近接した部位で、かつロータ２の端面（摩擦面２ａと反対側の面）に近接した部位に配設されている。従って、温度ヒューズ１３は、樹脂部材６の表面近くの部位に配設されることになり、温度ヒューズ１３の表面を樹脂部材６は薄膜状に覆っているだけである。
【００３６】
次に、本発明の特徴部分である、電磁クラッチのステータ部分の組付方法（電磁コイル５、温度ヒューズ１３、およびコイルスプール１４のコイルハウジング４内への組付方法）について説明する。
図４および図８は、電磁コイル５を巻線する前の、コイルスプール１４単体の状態を示しており、まず、電磁コイル５の巻始め側端部をコイルスプール１４のコイル取り出し部１４ｉの穴１４ｊよりコイルスプール１４の内側に挿入した後に、コイルスプール１４の円筒面上に電磁コイル５を若干量巻線する。しかるのち、電磁コイル５のコイル線５ａを一方の切欠き部１４ｇからコイルスプール１４の外側に取り出し、他方の切欠き部１４ｇから再度、コイルスプール１４の内側に挿入し、コイルスプール１４の円筒面上への電磁コイル５の巻線を継続し、この巻線を終了した後に、電磁コイル５の巻終わり側端部をコイルスプール１４のコイル取り出し部１４ｉの穴１４ｊよりコイルスプール１４の外側に取り出す。図９はこの電磁コイル５のコイル線５ａの途中をコイルスプール１４の外側に取り出して、巻線を完了した状態を示している。
【００３７】
次に、図１０に示すように、このコイル線５ａをその中間部位にて切断し、その切断端部を切欠き部１４ｇを起点としてコイルスプール１４の円周方向の反対側へ折り曲げる。そして、温度ヒューズ１３を２つの爪片１４ｃ、１４ｄを弾性的に押し広げながら、円弧状保持面１４ｆに嵌着保持する。この状態では、図７（ａ）に示すように、温度ヒューズ１３には２つの爪片１４ｃ、１４ｄの弾性的な保持力が作用するので、温度ヒューズ１３を確実に円弧状保持面１４ｆに嵌着保持できる。
【００３８】
次に、温度ヒューズ１３の両端のリード線１３ａを結線部５ｂにて電磁コイル５のコイル線５ａに電気接続する。図１０はこの温度ヒューズ１３のリード線１３ａの電気接続完了後の状態を示している。
以上により、コイルスプール１４に対する、電磁コイル５の巻線及び温度ヒューズ１３の装着が完了する。
【００３９】
次に、このコイルスプール１４部分をコイルハウジング４内に組付ける。このとき、温度ヒューズ１３がコイルハウジング４の内周側円筒部４ａの先端部側に位置するようにして、コイルスプール１４部分をコイルハウジング４内に組付ける。また、このとき、電磁コイル５の巻始め、巻終わり側の両端部５ｃ、５ｄを、コイルハウジング４の内外両円筒部４ａ、４ｂの中間側面部の穴（図示せず）を通してコイルハウジング４の外部に取り出して、この両端部５ｃ、５ｄをコネクタ１５の電気端子１５ａにフュージングにて電気的に接続しておく。
【００４０】
しかる後、樹脂部材６を構成する溶融樹脂をコイルハウジング４内に注入して成形することにより、コイルハウジング４内に電磁コイル５、コイルスプール１４および温度ヒューズ１３が樹脂部材６によって固定、保持される。また、コネクタ１５の樹脂ケース部も樹脂部材６と同一樹脂にて同時に成形される。
ここで、樹脂部材６は前述したように比較的低温（１３０〜１４０°Ｃ程度）で成形できる樹脂材料を用いているため、この成形時の熱で温度ヒューズ１３が開放（溶断）される恐れはない。また、樹脂部材６の成形温度は樹脂製コイルスプール１４の熱変形温度よりも十分低い温度であるので、樹脂部材６の成形によってコイルスプール１４が変形、劣化する恐れもない。
【００４１】
以上により、コイルスプール１４部分のコイルハウジング４内への組付を終了できる。
次に、上記構成において第１実施形態の作動を説明する。
まず、圧縮機の正常運転時について述べると、自動車エンジンのクランクプーリの回転が図示しないベルトを介してプーリ１に伝達され、このプーリ１と一体にロータ２は常時回転している。
【００４２】
上記の状態において、自動車用空調装置を作動させるため、電磁コイル５に通電されると、コイルハウジング４からロータ２、およびアーマチャ８を経てコイルハウジング４に戻る磁気回路Ｘ（図１参照）に磁束が流れる。これにより、ロータ２の摩擦面２ａとアーマチャ８との間に電磁吸引力が発生するので、アーマチャ８は弾性部材９の軸方向弾性力（図１の左方向への力）に抗してロータ２の摩擦面２ａに吸引、吸着される。
【００４３】
この結果、ロータ２とアーマチャ８が一体となって回転し、さらにアーマチャ８からリベット１０、弾性部材９、および保持部材１１を介してハブ１２に回転が伝達される。このハブ１２には圧縮機の回転軸が一体に結合されているので、この圧縮機の回転軸にプーリ１の回転が伝達され、圧縮機が作動する。
ここで、圧縮機の正常運転時には、ゴム製の弾性部材９が圧縮機の作動によるトルク変動を吸収する役割も果たしている。
【００４４】
ところで、上記圧縮機の正常作動時に、電磁コイル５は通電により発熱するが、本実施形態では、温度ヒューズ１３をコイルハウジング４の内周側円筒部４ａに近接して配設しているので、温度ヒューズ１３周囲の熱は、樹脂よりも熱伝導性が良好な、磁性体金属からなるコイルハウジング４側に放熱されるので、温度ヒューズ１３周囲の温度は、熱伝導度が低い樹脂部材６の中央部内に位置している場合に比してかなり低い温度となる。
【００４５】
そのため、電磁コイル５が発熱しても、その発熱の影響を受けて、温度ヒューズ１３が誤作動し、開放状態となる可能性を著しく低減できる。
一方、圧縮機が焼きつき等の重大故障を起こしてロックすると、圧縮機の回転軸側に結合されているアーマチャ８は回転不能となるので、このアーマチャ８上を滑りながらロータ２が回転する。その結果、このアーマチャ８とロータ２との滑り接触部分が摩擦熱により異常に温度上昇する。
【００４６】
このとき、コイルハウジング４は樹脂よりも熱伝導度が高いので、コイルハウジング４のうち、ロータ２の端面に近接した部分、すなわち内外周円筒部４ａ、４ｂの先端部はロータ２の温度上昇による熱を受けて速やかに温度上昇する。そのため、温度ヒューズ１３は、その表面側に位置する薄膜状の樹脂部材６を通して受熱する熱量に加えて、上記コイルハウジング４の内周側円筒部４ａの先端部を通して受熱するため、ロータ２の温度上昇に対して応答よく温度上昇する。
【００４７】
これにより、圧縮機のロック発生後、短時間で温度ヒューズ１３がその開放（溶断）温度まで上昇して開放状態となり、電磁コイル５への通電を遮断する。
（第２実施形態）
第１実施形態では、温度ヒューズ１３を配設する凹部１４ｂをコイルスプール１４の内周角部に形成する手段として、この内周角部にロータ２の摩擦面２ａから離れる方向に傾斜した傾斜面１４ａを形成しているが、第２実施形態では、この傾斜面１４ａの代わりに段付部１４ｋを形成するものである。
【００４８】
すなわち、図７（ｂ）に示すように、第２実施形態では、コイルスプール１４の内周角部に、ロータ２の摩擦面２ａから離れる方向に凹む段付部１４ｋを形成し、この段付部１４ｋにより温度ヒューズ１３配設のための凹所１４ｂを形成するようにしたものである。
（第３実施形態）
第３実施形態は、第１実施形態による傾斜面１４ａと第２実施形態による段付部１４ｋとを組み合わせるようにしたものである。すなわち、図７（ｃ）に示すように、第３実施形態では、コイルスプール１４の内周角部に、上気した傾斜面１４ａと段付部１４ｋの両方を形成して、この両者の組み合わせにより、温度ヒューズ１３配設のための凹所１４ｂを形成するようにしたものである。
（第４実施形態）
第４実施形態は樹脂部材６の成形方法に関する他の例であり、第１実施形態では、樹脂部材６を構成する樹脂材料として、成形温度が温度ヒューズ１３の溶断（開放）温度およびコイルスプール１４の成形（耐熱）温度より十分低い材料を選択して、樹脂部材６の成形を行っているが、第４実施形態では樹脂部材６を構成する樹脂材料として、成形温度が温度ヒューズ１３の開放温度より高い（例えば、２５０°Ｃ）ナイロン等の樹脂材料を用いるものである。
【００４９】
このために、第４実施形態では、まず、温度ヒューズ１３をコイルスプール１４の内周角部に装着する前に、この成形温度が高い樹脂材料の溶融樹脂をコイルハウジング４内に注入し成形することにより、温度ヒューズ１３以外の部分（電磁コイル５、コイルスプール１４）をコイルハウジング４に保持固定する。このとき、コイルスプール１４の内周角部における温度ヒューズ１３配設部位には成形樹脂が侵入しないようにしておく。
【００５０】
次に、温度ヒューズ１３をコイルスプール１４の内周角部に装着するとともに、温度ヒューズ１３の両端のリード線１３ａを電磁コイル５のコイル線５ａに電気接続した後に、温度ヒューズ１３の周辺部のみ、ポッティング法等により低成形温度の樹脂（前述のエポキシ樹脂、あるいはシリコンゴム等）を成形する。
このように、第４実施形態は樹脂部材６として、温度ヒューズ１３の周辺部のみ、温度ヒューズ１３の溶断（開放）温度より成形温度の低い低成形温度の樹脂を用い、温度ヒューズ１３の周辺部以外の部分には、温度ヒューズ１３の溶断（開放）温度より成形温度が高い高成形温度の樹脂を用いるものである。
【００５１】
なお、第４実施形態では樹脂部材６とコイルスプール１４が同種の樹脂材料であるので、樹脂部材６の成形時にコイルスプール１４はその成形温度近くまで加熱されることになるが、樹脂部材６の成形時間は短時間であるので、コイルスプール１４の変形、劣化等が生じる恐れはない。
（第５実施形態）
第５実施形態は樹脂部材６の成形方法として、第４実施形態を変形したものであり、温度ヒューズ１３をコイルスプール１４の内周角部に装着し、そのリード線１３ａを電磁コイル５のコイル線５ａに電気接続した後に、温度ヒューズ１３の周辺部のみ、ポッティング法等により低成形温度の樹脂（前述のエポキシ樹脂、あるいはシリコンゴム等）を成形する。
【００５２】
これより、温度ヒューズ１３の周辺部を上記低成形温度の樹脂により断熱できる。そこで、次に、温度ヒューズ１３の溶断（開放）温度より成形温度が高い高成形温度の樹脂を用いて、樹脂部材６の成形を行っても、温度ヒューズ１３が溶断（開放）することはない。また、前述のエポキシ樹脂、あるいはシリコンゴム等は一旦、成形され、硬化すると、成形温度より高い温度にて加熱されても、短時間で軟化、溶融することはないので、問題は発生しない。
（他の実施形態）
なお、上述の実施形態は、自動車用空調装置の冷媒圧縮用圧縮機に本発明を適用した場合について説明したが、本発明はこのような用途に限らず、種々な用途の機器に対して広く適用可能であることはもちろんである。
【図面の簡単な説明】
【図１】本発明の第１実施形態を示す縦断面図で、図２のＢ−Ｂ断面を示す。
【図２】図１の左側面図である。
【図３】図１の右側面図である。
【図４】図１に示すコイルスプール単体の正面図である。
【図５】（ａ）は図４のＨ−Ｈ断面図、（ｂ）は図４のＩ−Ｉ断面図である。
【図６】図１に示すコイルスプール単体の背面図である。
【図７】図１に示す温度ヒューズ配設部の拡大断面図で、（ａ）は第１実施形態の断面図、（ｂ）は第２実施形態の断面図、（ｃ）は第３実施形態の断面図である。
【図８】図１に示すコイルスプール単体における温度ヒューズ配設部の拡大正面図である。
【図９】図１に示すコイルスプールに電磁コイルを巻線した後における温度ヒューズ配設部の拡大正面図である。
【図１０】図１に示すコイルスプールに温度ヒューズを装着した後における温度ヒューズ配設部の拡大正面図である。
【図１１】本発明の第１実施形態における電磁コイルの電気結線図である。
【符号の説明】
１、２…プーリ、ロータ（駆動側回転部材）、４…コイルハウジング、
４ａ…内周側円筒部、４ｂ…外周側円筒部、５…電磁コイル、６…樹脂部材、
８…アーマチャ、９…弾性部材、１０…リベット、１１…保持部材、１２…ハブ（従動側回転部材）、１３…温度ヒューズ、１４コイルスプール、
１４ａ…傾斜面、１４ｂ…凹所、１４ｃ、１４ｄ…爪片、１４ｋ…段付部。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic clutch for intermittently transmitting power, and is suitable for driving a compressor in a refrigeration cycle of an automotive air conditioner.
[0002]
[Prior art]
Conventionally, a compressor of a refrigeration cycle of an automobile air conditioner is connected to an engine via an electromagnetic clutch, and power transmission from the engine is interrupted by the electromagnetic clutch.
By the way, when the compressor has a malfunction such as burn-in and the rotation shaft is locked, an excessive force is applied to the belt of the engine power transmission device, and this belt is damaged. Once this problem such as damage to the belt occurs, engine auxiliary equipment such as a water pump for circulating engine cooling water and a battery charging generator become inoperable, causing a serious situation that the engine is shut down. Measures to do this are necessary.
[0003]
Therefore, conventionally, the following measures are generally taken. That is, in an electromagnetic clutch having an input-side rotor that is rotated by receiving power from the engine side, and an output-side armature that is rotated by being attracted to the input-side rotor by an electromagnetic attraction force of an electromagnetic coil. When the machine is locked, the armature on the output side cannot rotate, and the rotor rotates while sliding relative to the armature, so that the temperature of the sliding contact portion rises abnormally.
[0004]
Therefore, paying attention to the abnormal rise in temperature at the sliding contact portion between the armature and the rotor, a thermal fuse that is blown by this abnormal rise in temperature is installed, and the current supply to the electromagnetic coil is cut off by the blow of this thermal fuse. Thus, an excessive force is prevented from being applied to the belt by putting the electromagnetic clutch in a power cut-off state. As a prior art in which such a thermal fuse is installed, there is one described in Japanese Patent Application Laid-Open No. 57-51025. In this prior art, a coil spool (winding frame) for holding the electromagnetic coil is used as a coil housing. While being fixed in the (fixed magnetic pole member), a thermal fuse is installed in a portion of the coil spool facing the rotor end surface.
[0005]
[Problems to be solved by the invention]
However, in the above-described prior art, the installation location of the thermal fuse is specifically set at a substantially intermediate portion between the inner peripheral portion and the outer peripheral portion of the side surface extending in the radial direction of the coil spool. Since the axial length of the coil spool is reduced by the installation space of the thermal fuse, and as a result, the number of turns of the electromagnetic coil held by the coil spool is reduced, in order to ensure the required electromagnetic attractive force, There is a problem that the power consumption of the electromagnetic coil increases.
[0006]
Further, according to experiments and examinations by the present inventors, it has been found that the above-described conventional technique also causes the following problems.
That is, since the thermal fuse is installed at a location away from the coil housing so as to be covered with the resin member that insulates and fixes the electromagnetic coil and the coil spool, the heat around the thermal fuse is hardly released to the outside.
[0007]
For this reason, when the electromagnetic coil is energized and generates heat when the compressor is normal, the temperature fuse peripheral part may rise due to the influence of this heat generation and may rise above the fusing temperature of the temperature fuse. Regardless, a malfunction may occur in which the thermal fuse blows.
Also, when the compressor is locked, the temperature rise at the sliding contact portion between the armature and the rotor is blocked by the resin member, and the heat at the sliding contact portion is not easily transferred to the thermal fuse, so the time until the thermal fuse blows Takes a long time and causes a problem of poor responsiveness. Due to the deterioration of the responsiveness, the temperature of the electromagnetic clutch bearing (ball bearing) may be increased and locked before the thermal fuse is blown.
[0008]
The present invention has been made in view of the above points, and firstly, it is an object of the present invention to suppress a reduction in winding space of an electromagnetic coil accompanying installation of a thermal fuse.
The second object of the present invention is to provide an electromagnetic clutch that can reduce the possibility of malfunction of a thermal fuse during normal operation and can improve the responsiveness of fusing of a thermal fuse during clutch slipping.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention employs the following technical means. Claims 1 to9In the described invention, the drive side rotation members (1, 2) that rotate by receiving the rotational force from the rotation drive source, the driven side rotation member (12) coupled to the rotation shaft of the driven side device, An electromagnetic coil (5) that generates an attractive force, a coil housing (4) that houses and fixes the electromagnetic coil (5), and an electromagnetic attractive force generated by the electromagnetic coil (5) drive-side rotating member (1, 2) an armature (8) attracted to the friction surface (2a), and an elastic coupling mechanism (9, 10, 11) for elastically coupling the driven side rotating member (12) and the armature (8). In addition, a thermal fuse (13) is disposed in the coil housing (4) at a position close to the friction surface (2a) of the drive side rotating members (1, 2), and the thermal fuse (13) , Fusing above a predetermined temperature, electromagnetic coil 5) In the electromagnetic clutch which cuts off the energization to the coil housing (4), an annular coil spool (14) is arranged in the coil housing (4), and the electromagnetic coil (5) is placed on the coil spool (14). In addition to winding, a recess (14b) is formed in the inner circumferential corner of the coil spool (14) located on the friction surface (2a) side of the drive side rotating member (1, 2). It is characterized in that a thermal fuse (13) is disposed at the location (14b).
  Further, in the invention according to claim 1, in addition to the above, the electromagnetic coil (5) is also wound around the outer peripheral side region of the recess (14b) in the coil spool (14)..
[0010]
According to this configuration, since the thermal fuse (13) is disposed in the recess (14b) formed in the inner peripheral corner of the coil spool (14), it extends in the radial direction of the coil spool as in the prior art. The axial length of the entire coil spool is reduced with the installation of the thermal fuse, as in the case where the thermal fuse (13) is disposed at a substantially intermediate portion between the inner peripheral portion and the outer peripheral portion of the side surface. Only the inner circumferential corner of the coil spool (14) needs to reduce the space locally.
[0011]
As a result, the decrease in the number of turns of the electromagnetic coil held on the coil spool (14) can be greatly suppressed as compared with the prior art, and the increase in the power consumption of the electromagnetic coil to secure the required electromagnetic attractive force is suppressed to a small value. The effect of being able to do it is great.
Moreover, in addition to the above, it is possible to reduce the malfunction of the thermal fuse and improve the response. That is, during normal operation of a driven device such as a compressor, even if the electromagnetic coil (5) generates heat when energized, the temperature fuse (13) is positioned at the inner peripheral corner of the coil spool (14), and the coil housing ( Since the heat around the thermal fuse is close to the wall of 4), the heat around the thermal fuse is dissipated to the coil housing (4) side made of magnetic metal, which has better thermal conductivity than the resin. The temperature is considerably lower than that in the case where the thermal conductivity is located in the central portion of the resin member.
[0012]
Therefore, even if the electromagnetic coil (5) generates heat, the possibility of the thermal fuse (13) malfunctioning due to the generated heat and fusing can be significantly reduced.
On the other hand, when the driven device is locked due to a serious failure such as seizure, the sliding contact portion between the armature (8) and the driving side rotating member (1, 2) abnormally rises in temperature due to frictional heat. At this time, since the coil housing (4) has higher thermal conductivity than the resin, the end of the coil housing (4) adjacent to the friction surface (2a) of the drive side rotating member (1, 2) is on the drive side. The temperature rises rapidly upon receiving heat from the temperature rise of the rotating members (1, 2). And since the thermal fuse (13) receives heat through the end part of the coil housing (4), the temperature rises with good response to the temperature rise of the drive side rotating members (1, 2).
[0013]
  As a result, the thermal fuse (13) rises to its fusing temperature and blows in a short time after the driven device is locked, and the electromagnetic coil (5) can be cut off. Therefore, before the thermal fuse (13) is blown, it is possible to reliably prevent a problem that the bearing of the electromagnetic clutch rises in temperature and locks.
According to the second aspect of the present invention, in the coil spool (14), the driving side rotating member (1, 2) is disposed at the inner peripheral corner located on the friction surface (2a) side of the driving side rotating member (1, 2). An inclined surface (14a) inclined in a direction away from the friction surface (2a) is formed, and a recess (14b) is formed by the inclined surface (14a), and a thermal fuse (13) is formed in the recess (14b). ) Is provided.
According to the third aspect of the present invention, in the coil spool (14), the driving side rotating member (1, 2) is disposed at the inner peripheral corner located on the friction surface (2a) side of the driving side rotating member (1, 2). A stepped portion (14k) recessed in a direction away from the friction surface (2a) is formed, and a recess (14b) is formed by the stepped portion (14k), and a thermal fuse (14b) is formed in the recess (14b). 13) is provided.
In the invention according to claim 4, of the coil spool (14), the driving side rotating member (1, 2) is disposed at the inner peripheral corner located on the friction surface (2a) side of the driving side rotating member (1, 2). An inclined surface (14b) that is inclined in a direction away from the friction surface (2a), and a stepped portion (14k) that is recessed in a direction away from the friction surface (2a) of the drive side rotating members (1, 2), A recess (14b) is formed by the inclined surface (14a) and the stepped portion (14k), and a thermal fuse (13) is disposed in the recess (14b).
In the invention according to claim 5, a recess (14b) is formed in the inner peripheral corner located on the friction surface (2a) side of the drive side rotating member (1, 2) of the coil spool (14), A thermal fuse (13) is disposed in the recess (14b),
  In addition,The coil housing (4) is formed in a double cylindrical shape having a U-shaped cross section. Of the double cylindrical shape of the coil housing (4), the friction surface (2a) of the inner peripheral side cylindrical portion (4a). An inclined surface (4c) inclined from the outer peripheral surface to the inner peripheral surface side is formed at the side tip, and a recess (14b) is formed along the inclined surface (4c).
[0014]
According to this configuration, the inclined surface (4c) is utilized by forming the recess (14b) along the tip inclined surface (4c) of the inner peripheral side cylindrical portion (4a) of the coil housing (4). The recess (14b) can be enlarged, and the decrease in the number of turns of the electromagnetic coil (5) can be more effectively suppressed.
According to a sixth aspect of the present invention, in the electromagnetic clutch according to any one of the second to fifth aspects, the electromagnetic coil (5) is wound around the outer peripheral side region of the recess (14b) in the coil spool (14). LinedIt is characterized by that.
In the invention according to claim 7, in the electromagnetic clutch according to any one of claims 1 to 6, the coil spool (14) is formed of an elastic resin,
Claw pieces (14c, 14d) that elastically hold the thermal fuse (13) are integrally formed at the inner peripheral corner.
According to an eighth aspect of the present invention, in the electromagnetic clutch according to any one of the first to seventh aspects, the coil spool (14) takes out the electromagnetic coil (5) in the vicinity of both ends of the thermal fuse (13). A notch (14 g) for
The electromagnetic coil (5) taken out from the notch (14g) is cut and electrically connected to both ends of the thermal fuse (13).
According to a ninth aspect of the present invention, in the electromagnetic clutch according to any one of the first to eighth aspects, the coil spool (14) and the thermal fuse (13) are resin members formed in the coil housing (4). It is fixed and held by (6).
  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description later mentioned.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments shown in the drawings will be described below.
(First embodiment)
In FIGS. 1 and 2, reference numeral 1 denotes a driving pulley which is rotated by receiving a rotational force from an automobile engine via a belt (not shown). The pulley 1 is integrally formed with a pulley portion 1a having a multiple V groove with which a multiple V belt is engaged, and is made of an iron-based metal.
[0016]
Reference numeral 2 denotes a drive-side rotor formed in a double cylindrical shape having a U-shaped cross section, which is made of an iron-based metal (ferromagnetic material), and is integrally joined to the pulley 1 by welding means or the like. Yes. A bearing 3 is disposed on the inner peripheral portion of the rotor 2, and the rotor 2 is rotatably supported by the bearing 3 on a cylindrical protrusion of a front housing of a compressor (not shown). Here, the compressor is for refrigerant compression of a refrigeration cycle of an automotive air conditioner.
[0017]
4 is a coil housing that serves as a fixed magnetic pole member, and is formed of a ferrous metal (ferromagnetic material) in a double cylindrical shape with a U-shaped cross section having an inner peripheral cylindrical portion 4a and an outer peripheral cylindrical portion 4b. Has been. An annular resin coil spool 14 is disposed inside the coil housing 4 so as to be positioned on the inner peripheral cylindrical portion 4 a of the coil housing 4. An electromagnetic coil 5 is wound on the coil spool 14 and is held and fixed. The coil spool 14 and the electromagnetic coil 5 are insulated and fixed in the coil housing 4 by a resin member 6.
[0018]
Here, in this example, the resin member 6 is formed by injecting a resin material that can be molded at a relatively low temperature (130 to 140 ° C.) such as an epoxy resin or an unsaturated polyester into the internal space of the coil housing 4. is there. The resin material constituting the coil spool 14 is preferably a resin that is excellent in heat resistance to withstand the heat generated by the electromagnetic coil 5 and has a certain degree of rigidity. For example, nylon, polyphenylene sulfide, polybutylene terephthalate, or the like is used. Since the heat deformation temperature of these resins is sufficiently higher (200 ° C. or higher) than the molding temperature (130 to 140 ° C.) of the resin member 6, there is no problem due to the molding of the resin member 6.
[0019]
On the other hand, the coil housing 4 is disposed in the inner space having a U-shaped cross section of the rotor 2 via a minute gap, so that the rotor 2 is rotatable with respect to the coil housing 4. A stay 7 formed of a ferrous metal in a substantially square shape is joined to the back surface of the coil housing 4 by spot welding or the like. A circular hole 7a through which a cylindrical protrusion (not shown) of the front housing of the compressor passes is formed at the center of the stay 7.
[0020]
The coil housing 4 is fixed to the front housing of the compressor via the stay 7.
On the friction surface 2a extending in the radial direction of the rotor 2, ring-shaped magnetic shielding members 2b and 2c made of copper (non-magnetic material) are disposed. Further, a friction material 2d is disposed at the magnetic shielding member 2b so as to improve the transmission torque.
[0021]
Reference numeral 8 denotes an armature disposed to face the friction surface 2a of the rotor 2 and is formed of a ferrous metal (ferromagnetic material) in a ring shape. The armature 8 is held at a predetermined distance from the friction surface 2a of the rotor 2 by the elastic force of a rubber elastic member 9 described later when the electromagnetic coil 5 is not energized. The armature 8 is formed with an arc-shaped magnetic blocking groove 8a extending in the circumferential direction.
[0022]
A magnetic circuit (refer to a one-dot chain line X in FIG. 1) through which a magnetic flux generated by energizing the electromagnetic coil 5 flows is constituted by the rotor 2, the coil housing 4, and the armature 8.
Reference numeral 10 denotes a rivet made of an iron-based metal, which connects the armature 8 to the holding member 11 through a rubber elastic member 9. This connecting structure will be described in detail. Three rivets 10 are arranged at intervals of 120 degrees as shown in FIG. 2, and are caulked and fixed integrally to the armature 8 at the heads 10a. A cylindrical rubber elastic member 9 is integrally bonded and fixed to the outer peripheral surface of the shaft portion 10 b of the rivet 10, and the outer peripheral surface of the elastic member 9 is connected to the inner peripheral surface of the cylindrical holding portion 11 a of the holding member 11. It is press-fitted and fixed.
[0023]
The holding member 11 is formed of an iron-based metal, and has a substantially equilateral triangular shape in which the cylindrical holding portion 11a is integrally formed near the top. The holding member 11 has a circular hole 11b at the center thereof, and a hub 12 is caulked and fixed to the peripheral edge of the circular hole 11b by three rivets 12a. The hub 12 is formed of an iron-based metal, and a rotation shaft (not shown) of the compressor is fixed to the inner periphery of the central cylindrical portion 12b by spline coupling or the like. The rotating shaft of the compressor is integrally fastened and fixed by a bolt (not shown).
[0024]
Further, as the material of the elastic member 9, rubber that exhibits excellent characteristics in terms of torque transmission and torque fluctuation absorption with respect to the use environment temperature range (-30 ° C to 115 ° C) of the automobile is used. Specifically, rubbers such as chlorinated butyl rubber, acrylonitrile butadiene rubber, and ethylene propylene rubber are preferable.
In this example, the pulley 1 and the rotor 2 constitute a driving side rotating member, and the hub 12 constitutes a driven side rotating member. The elastic member 9, the rivet 10, and the holding member 11 constitute an elastic connection mechanism that connects the hub (driven rotation member) 12 and the armature 8, and the elastic member 9 is elastic when the electromagnetic coil 5 is not energized. The armature 8 is held at a position separated from the friction surface 2a of the rotor 2 by force.
[0025]
Reference numeral 13 denotes a thermal fuse, which incorporates a temperature-sensitive member (resin member made of an organic compound) that melts at a predetermined temperature (184 ° C. in this example), and electrical connection between the contacts until the temperature-sensitive member melts. When the state is maintained and the temperature sensitive member is melted, the contacts are separated by the action of the spring, and the electrical connection state is cut off.
The temperature fuse 13 is formed in a substantially columnar shape in which these temperature sensitive members, contact mechanisms, springs, and the like are housed in a cylindrical case. When the compressor is locked, the thermal fuse 13 cannot rotate the armature 8, and the rotor 2 rotates while sliding relative to the armature 8, thereby detecting that the temperature of the sliding contact portion rises abnormally and shuts off. It will be a state.
[0026]
Therefore, it is necessary for the thermal fuse 13 to sense an abnormal temperature rise due to the sliding contact between the armature 8 and the rotor 2 when the compressor is locked, and to respond to heat generation of the electromagnetic coil 5 when the compressor is normal. It is necessary to prevent malfunction.
In consideration of the above points, in the present embodiment, the arrangement location of the thermal fuse 13 is set as follows. 4 to 6 show the shape of the coil spool 14 alone, and FIGS. 7A and 8 to 10 are enlarged views of the location where the thermal fuse 13 is disposed. Based on these drawings, the arrangement of the thermal fuse 13 will be described in detail. The coil spool 14 is separated from the friction surface 2a at the inner peripheral corner located on the friction surface 2a side of the rotor 2. An inclined surface 14a inclined in the direction is formed over the entire circumference.
[0027]
A recess 14 b is formed in the inner peripheral corner of the coil spool 14 by the inclined surface 14 a, and the inside of the recess 14 b is configured as a place where the thermal fuse 13 is disposed.
Here, the outer side of the inclined surface 14a is not continuously inclined over the entire circumference, and the outer surface of the inclined surface 14a is blocked from being inclined at predetermined intervals. The inclined blocking portion on the outer surface forms a reinforcing rib 14e.
[0028]
An inclined surface 4c (see FIG. 7A) that is inclined from the outer peripheral surface toward the inner peripheral surface (to reduce the cross-sectional area) is formed at the tip of the inner peripheral cylindrical portion 4a of the coil housing 4. It is. In the magnetic circuit X of FIG. 1, the inclined surface 4c prevents the magnetic flux from going directly to the intermediate portion in the radial direction of the friction surface 2a of the rotor 2 so that the magnetic flux goes to the inner peripheral cylindrical portion side of the rotor 2. Is to do.
[0029]
The recess 14b is enlarged by the inclined surface 4c, so that the arrangement area of the thermal fuse 13 can be enlarged.
As shown in an enlarged view in FIGS. 7A and 8 to 10, two claw pieces 14 c and 14 d that elastically hold the thermal fuse 13 are formed on the inclined surface 14 a of the inner peripheral corner of the coil spool 14. It is integrally molded. Here, the one claw piece 14c is formed so as to extend obliquely in the inner circumferential direction of the coil spool 14 along the tip inclined surface 4c of the inner circumferential side cylindrical portion 4a of the coil housing 4. In addition, it is easy to secure the arrangement area of the thermal fuse 13 while suppressing a decrease in the winding space of the electromagnetic coil 5.
[0030]
The interval between the two claw pieces 14c and 14d is set to be a predetermined amount smaller than the cylindrical outer diameter of the thermal fuse 13 so that an elastic holding force acts on the thermal fuse 13.
Further, of the outer surface of the inclined surface 14 a, the portion where the thermal fuse 13 is disposed forms an arcuate holding surface 14 f along the outer peripheral surface of the thermal fuse 13.
[0031]
Further, the inner peripheral corner of the coil spool 14 is formed with a notch 14g for taking out a part of the electromagnetic coil 5 in the vicinity of both ends of the thermal fuse 13, and the electromagnetic coil taken out from the notch 14g. 5, a part of the coil wire 5a is cut, and the lead wire 13a at both ends of the thermal fuse 13 is electrically connected to the cut coil wire 5a at the connection portion 5b. Here, electrical and mechanical joining of the coil wire 5a and the lead wire 13a by the connecting portion 5b can be performed by means such as soldering, fusing, caulking, etc. In the illustrated example, an appropriate metal clamp is used. An example of caulking is shown.
[0032]
And in the range where the coil wire 5a of the electromagnetic coil 5 and the lead wire 13a of the thermal fuse 13 are disposed, a protruding piece 14h that protrudes obliquely toward the inner peripheral side is formed at the inner peripheral corner of the coil spool 14, The protruding piece 14h ensures electrical insulation between the coil 5 wound around the coil spool 14 and the coil wire 5a and the lead wire 13a.
[0033]
On the other hand, a coil take-out portion 14 i for taking out the winding start side end portion and winding end side end portion of the electromagnetic coil 5 is integrally formed on the coil spool 14. The coil take-out portion 14i is disposed at a portion of the coil spool 14 opposite to the friction surface 2a of the rotor 2 and 180 ° symmetrical in the circumferential direction with respect to the portion where the thermal fuse 13 is disposed. Two holes 14j for taking out both ends of the coil 5 are provided.
[0034]
Both end portions 5c and 5d (see FIG. 11) of the electromagnetic coil 5 are taken out of the coil housing 4 through holes (not shown) formed in the intermediate side surface portions of the inner and outer cylindrical portions 4a and 4b of the coil housing 4. Thus, it is electrically connected to an electrical terminal 15a (see FIG. 11) in the connector 15. FIG. 11 shows the electrical connection state after the assembly of the electromagnetic clutch is completed.
[0035]
In FIG. 1, the A portion of the coil housing 4 is omitted in order to avoid complication of the sectional illustration, and the hole is provided in the A portion.
By the way, the thermal fuse 13 is a part close to the outer peripheral wall surface of the inner peripheral side cylindrical portion 4a of the coil housing 4 and the end surface of the rotor 2 (the surface opposite to the friction surface 2a), as can be understood from FIG. It is arrange | positioned in the site | part close to. Therefore, the thermal fuse 13 is disposed near the surface of the resin member 6, and the resin member 6 only covers the surface of the thermal fuse 13 in a thin film shape.
[0036]
Next, a method for assembling the stator portion of the electromagnetic clutch (method for assembling the electromagnetic coil 5, the thermal fuse 13, and the coil spool 14 into the coil housing 4), which is a characteristic part of the present invention, will be described.
4 and 8 show a state of the coil spool 14 alone before winding the electromagnetic coil 5. First, the winding start side end portion of the electromagnetic coil 5 is used as the hole of the coil extraction portion 14 i of the coil spool 14. After inserting the coil spool 14 into the coil spool 14 from 14j, a certain amount of the electromagnetic coil 5 is wound on the cylindrical surface of the coil spool 14. After that, the coil wire 5a of the electromagnetic coil 5 is taken out of the coil spool 14 from one notch portion 14g, and inserted again into the coil spool 14 from the other notch portion 14g. After the winding of the electromagnetic coil 5 is continued and this winding is finished, the winding end side end of the electromagnetic coil 5 is taken out of the coil spool 14 from the hole 14j of the coil take-out portion 14i of the coil spool 14. . FIG. 9 shows a state in which the coil wire 5a of the electromagnetic coil 5 is taken out to the outside of the coil spool 14 and the winding is completed.
[0037]
Next, as shown in FIG. 10, the coil wire 5a is cut at an intermediate portion thereof, and the cut end portion is bent to the opposite side in the circumferential direction of the coil spool 14 from the notch portion 14g. Then, the thermal fuse 13 is fitted and held on the arc-shaped holding surface 14f while elastically expanding the two claw pieces 14c and 14d. In this state, as shown in FIG. 7A, since the elastic holding force of the two claw pieces 14c and 14d acts on the thermal fuse 13, the thermal fuse 13 is securely fitted to the arc-shaped holding surface 14f. You can keep wearing
[0038]
Next, the lead wires 13a at both ends of the thermal fuse 13 are electrically connected to the coil wire 5a of the electromagnetic coil 5 at the connection portion 5b. FIG. 10 shows a state after the electrical connection of the lead wire 13a of the thermal fuse 13 is completed.
Thus, the mounting of the winding of the electromagnetic coil 5 and the thermal fuse 13 on the coil spool 14 is completed.
[0039]
Next, the coil spool 14 is assembled in the coil housing 4. At this time, the coil spool 14 is assembled in the coil housing 4 so that the thermal fuse 13 is positioned on the tip end side of the inner peripheral side cylindrical portion 4 a of the coil housing 4. At this time, both ends 5c and 5d on the winding start and winding end sides of the electromagnetic coil 5 are passed through holes (not shown) in the intermediate side surfaces of the inner and outer cylindrical portions 4a and 4b of the coil housing 4. The two ends 5c and 5d are taken out to the outside and electrically connected to the electric terminal 15a of the connector 15 by fusing.
[0040]
Thereafter, the molten resin constituting the resin member 6 is injected into the coil housing 4 and molded, so that the electromagnetic coil 5, the coil spool 14 and the thermal fuse 13 are fixed and held in the coil housing 4 by the resin member 6. The Further, the resin case portion of the connector 15 is also simultaneously molded with the same resin as the resin member 6.
Here, since the resin member 6 is made of a resin material that can be molded at a relatively low temperature (about 130 to 140 ° C.) as described above, the thermal fuse 13 may be opened (blown) by the heat during the molding. There is no. Further, since the molding temperature of the resin member 6 is sufficiently lower than the thermal deformation temperature of the resin coil spool 14, there is no possibility that the coil spool 14 is deformed or deteriorated by the molding of the resin member 6.
[0041]
Thus, the assembly of the coil spool 14 portion into the coil housing 4 can be completed.
Next, the operation of the first embodiment in the above configuration will be described.
First, the normal operation of the compressor will be described. The rotation of the crank pulley of the automobile engine is transmitted to the pulley 1 via a belt (not shown), and the rotor 2 is always rotated integrally with the pulley 1.
[0042]
When the electromagnetic coil 5 is energized to operate the automobile air conditioner in the above state, the magnetic flux is applied to the magnetic circuit X (see FIG. 1) that returns from the coil housing 4 to the coil housing 4 through the rotor 2 and the armature 8. Flows. As a result, an electromagnetic attraction force is generated between the friction surface 2a of the rotor 2 and the armature 8, so that the armature 8 resists the axial elastic force of the elastic member 9 (the force in the left direction in FIG. 1). The two friction surfaces 2 a are sucked and adsorbed.
[0043]
As a result, the rotor 2 and the armature 8 rotate together, and the rotation is further transmitted from the armature 8 to the hub 12 via the rivet 10, the elastic member 9, and the holding member 11. Since the rotation shaft of the compressor is integrally coupled to the hub 12, the rotation of the pulley 1 is transmitted to the rotation shaft of the compressor and the compressor is operated.
Here, during normal operation of the compressor, the rubber elastic member 9 also plays a role of absorbing torque fluctuations caused by the operation of the compressor.
[0044]
By the way, during normal operation of the compressor, the electromagnetic coil 5 generates heat when energized. However, in the present embodiment, the temperature fuse 13 is disposed close to the inner peripheral side cylindrical portion 4a of the coil housing 4, Since the heat around the thermal fuse 13 is radiated to the coil housing 4 side made of a magnetic metal, which has better thermal conductivity than the resin, the temperature around the thermal fuse 13 is the temperature of the resin member 6 with low thermal conductivity. The temperature is considerably lower than that in the case of being located in the central portion.
[0045]
Therefore, even if the electromagnetic coil 5 generates heat, the possibility of the thermal fuse 13 malfunctioning and being opened due to the influence of the heat generation can be significantly reduced.
On the other hand, when the compressor is locked due to a serious failure such as burn-in, the armature 8 coupled to the rotary shaft side of the compressor cannot be rotated, so the rotor 2 rotates while sliding on the armature 8. As a result, the sliding contact portion between the armature 8 and the rotor 2 abnormally rises due to frictional heat.
[0046]
At this time, since the coil housing 4 has a higher thermal conductivity than the resin, a portion of the coil housing 4 that is close to the end surface of the rotor 2, that is, the front end portions of the inner and outer cylindrical portions 4a and 4b, is caused by the temperature rise of the rotor 2. The temperature rises rapidly upon receiving heat. Therefore, in addition to the amount of heat received through the thin film-like resin member 6 located on the surface side, the thermal fuse 13 receives heat through the distal end portion of the inner peripheral side cylindrical portion 4a of the coil housing 4, so that the temperature of the rotor 2 is increased. The temperature rises with good response to the rise.
[0047]
As a result, the thermal fuse 13 rises to its open (melting) temperature in a short time after the compressor is locked, and is opened, and the electromagnetic coil 5 is de-energized.
(Second Embodiment)
In the first embodiment, as a means for forming the concave portion 14b in which the thermal fuse 13 is disposed in the inner peripheral corner portion of the coil spool 14, an inclined surface inclined in a direction away from the friction surface 2a of the rotor 2 at the inner peripheral corner portion. Although 14a is formed, in 2nd Embodiment, the step part 14k is formed instead of this inclined surface 14a.
[0048]
That is, as shown in FIG. 7B, in the second embodiment, a stepped portion 14k that is recessed in the direction away from the friction surface 2a of the rotor 2 is formed at the inner peripheral corner of the coil spool 14, and this stepped portion is formed. A recess 14b for arranging the thermal fuse 13 is formed by the portion 14k.
(Third embodiment)
In the third embodiment, the inclined surface 14a according to the first embodiment and the stepped portion 14k according to the second embodiment are combined. That is, as shown in FIG. 7 (c), in the third embodiment, both the inclined surface 14a and the stepped portion 14k are formed on the inner peripheral corner of the coil spool 14, and a combination of both is formed. Thus, a recess 14b for disposing the thermal fuse 13 is formed.
(Fourth embodiment)
The fourth embodiment is another example relating to the molding method of the resin member 6. In the first embodiment, as the resin material constituting the resin member 6, the molding temperature is the fusing (opening) temperature of the thermal fuse 13 and the coil spool 14. The resin member 6 is molded by selecting a material that is sufficiently lower than the molding (heat-resistant) temperature. However, in the fourth embodiment, the molding temperature is the open temperature of the thermal fuse 13 as the resin material constituting the resin member 6. A higher (for example, 250 ° C.) resin material such as nylon is used.
[0049]
For this reason, in the fourth embodiment, first, before the thermal fuse 13 is mounted on the inner peripheral corner of the coil spool 14, a molten resin of a resin material having a high molding temperature is injected into the coil housing 4 and molded. As a result, portions (the electromagnetic coil 5 and the coil spool 14) other than the thermal fuse 13 are held and fixed to the coil housing 4. At this time, the molding resin is prevented from entering the portion where the thermal fuse 13 is disposed at the inner peripheral corner of the coil spool 14.
[0050]
Next, the thermal fuse 13 is attached to the inner peripheral corner of the coil spool 14, and the lead wires 13 a at both ends of the thermal fuse 13 are electrically connected to the coil wire 5 a of the electromagnetic coil 5. Then, a resin having a low molding temperature (such as the aforementioned epoxy resin or silicon rubber) is molded by a potting method or the like.
As described above, in the fourth embodiment, as the resin member 6, only the peripheral portion of the thermal fuse 13 is made of a resin having a molding temperature lower than the fusing (opening) temperature of the thermal fuse 13, and the peripheral portion of the thermal fuse 13 is used. For other parts, a resin having a high molding temperature higher than the fusing (opening) temperature of the thermal fuse 13 is used.
[0051]
In the fourth embodiment, since the resin member 6 and the coil spool 14 are made of the same type of resin material, the coil spool 14 is heated close to the molding temperature when the resin member 6 is molded. Since the molding time is short, there is no possibility that the coil spool 14 will be deformed or deteriorated.
(Fifth embodiment)
The fifth embodiment is a modification of the fourth embodiment as a method of molding the resin member 6, and the thermal fuse 13 is attached to the inner peripheral corner of the coil spool 14, and the lead wire 13 a is used as the coil of the electromagnetic coil 5. After electrical connection to the wire 5a, only a peripheral portion of the thermal fuse 13 is molded with a low molding temperature resin (such as the above-described epoxy resin or silicon rubber) by a potting method or the like.
[0052]
Thereby, the peripheral part of the thermal fuse 13 can be insulated by the resin having the low molding temperature. Therefore, even if the resin member 6 is molded using a resin having a higher molding temperature than the fusing (opening) temperature of the thermal fuse 13, the thermal fuse 13 will not be blown (opened). . Also, once the epoxy resin or silicon rubber described above is molded and cured, it does not soften or melt in a short time even when heated at a temperature higher than the molding temperature, so no problem occurs.
(Other embodiments)
In addition, although the above-mentioned embodiment demonstrated the case where this invention was applied to the compressor for refrigerant | coolant compression of an automotive air conditioner, this invention is not limited to such a use, but is wide with respect to the apparatus of various uses. Of course, it is applicable.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention, and shows a BB cross section of FIG.
FIG. 2 is a left side view of FIG.
FIG. 3 is a right side view of FIG. 1;
4 is a front view of a single coil spool shown in FIG. 1. FIG.
5A is a cross-sectional view taken along the line HH in FIG. 4, and FIG. 5B is a cross-sectional view taken along the line II in FIG.
6 is a rear view of a single coil spool shown in FIG. 1. FIG.
7 is an enlarged cross-sectional view of the thermal fuse arrangement portion shown in FIG. 1, where (a) is a cross-sectional view of the first embodiment, (b) is a cross-sectional view of the second embodiment, and (c) is a third embodiment. It is sectional drawing of a form.
8 is an enlarged front view of a thermal fuse disposition portion in the coil spool alone shown in FIG.
9 is an enlarged front view of a thermal fuse arrangement part after an electromagnetic coil is wound around the coil spool shown in FIG. 1;
10 is an enlarged front view of a thermal fuse arrangement portion after the thermal fuse is mounted on the coil spool shown in FIG.
FIG. 11 is an electrical connection diagram of the electromagnetic coil according to the first embodiment of the present invention.
[Explanation of symbols]
1, 2 ... pulley, rotor (drive side rotating member), 4 ... coil housing,
4a ... inner peripheral side cylindrical part, 4b ... outer peripheral side cylindrical part, 5 ... electromagnetic coil, 6 ... resin member,
8 ... Armature, 9 ... Elastic member, 10 ... Rivet, 11 ... Holding member, 12 ... Hub (driven rotation member), 13 ... Thermal fuse, 14 coil spool,
14a ... inclined surface, 14b ... recess, 14c, 14d ... claw piece, 14k ... stepped portion.

Claims

A drive-side rotating member (1, 2) that is formed of a magnetic body and rotates by receiving a rotational force from a rotational drive source;
A driven side rotating member (12) coupled to the rotating shaft of the driven side device;
An electromagnetic coil (5) that generates an electromagnetic attractive force when energized;
A coil housing (4) that is formed of a magnetic material and houses and fixes the electromagnetic coil (5);
An armature (8) formed of a magnetic material and attracted to the friction surface (2a) of the drive-side rotating member (1, 2) by an electromagnetic attractive force generated by the electromagnetic coil (5);
The driven-side rotating member (12) and the armature (8) are connected to each other, and when the electromagnetic coil (5) is not energized, the armature (8) is connected to the driving-side rotating member (1, 2) an elastic coupling mechanism (9, 10, 11) that is held at a position separated from the friction surface (2a);
In the coil housing (4), it is disposed at a portion close to the friction surface (2a) of the drive side rotating member (1, 2), and melts at a predetermined temperature or more to connect to the electromagnetic coil (5). In an electromagnetic clutch provided with a thermal fuse (13) for interrupting energization,
An annular coil spool (14) is disposed in the coil housing (4), and the electromagnetic coil (5) is wound on the coil spool (14).
In this coil spool (14), a recess (14b) is formed at an inner peripheral corner located on the friction surface (2a) side of the drive side rotating member (1, 2). 14b) is provided with the thermal fuse (13) ,
The electromagnetic clutch (5), wherein the electromagnetic coil (5) is wound around an outer peripheral side region of the recess (14b) in the coil spool (14) .

A drive-side rotating member (1, 2) that is formed of a magnetic body and rotates by receiving a rotational force from a rotational drive source;
A driven side rotating member (12) coupled to the rotating shaft of the driven side device;
An electromagnetic coil (5) that generates an electromagnetic attractive force when energized;
A coil housing (4) that is formed of a magnetic material and houses and fixes the electromagnetic coil (5);
An armature (8) formed of a magnetic material and attracted to the friction surface (2a) of the drive-side rotating member (1, 2) by an electromagnetic attractive force generated by the electromagnetic coil (5);
The driven-side rotating member (12) and the armature (8) are connected to each other, and when the electromagnetic coil (5) is not energized, the armature (8) is connected to the driving-side rotating member (1, 2) an elastic coupling mechanism (9, 10, 11) for holding at a position separated from the friction surface (2a);
In the coil housing (4), it is disposed at a portion close to the friction surface (2a) of the drive side rotating member (1, 2), and melts at a predetermined temperature or more to connect to the electromagnetic coil (5). In an electromagnetic clutch provided with a thermal fuse (13) for interrupting energization,
An annular coil spool (14) is disposed in the coil housing (4), and the electromagnetic coil (5) is wound on the coil spool (14).
Of the coil spool (14), the friction surface (2a) of the drive-side rotation member (1, 2) is formed on the inner peripheral corner located on the friction surface (2a) side of the drive-side rotation member (1, 2). An inclined surface (14a) inclined in a direction away from
A recess (14b) is formed by the inclined surface (14a), and the thermal fuse (13) is disposed in the recess (14b) .

A drive-side rotating member (1, 2) that is formed of a magnetic body and rotates by receiving a rotational force from a rotational drive source;
A driven side rotating member (12) coupled to the rotating shaft of the driven side device;
An electromagnetic coil (5) that generates an electromagnetic attractive force when energized;
A coil housing ( 4) that is formed of a magnetic material and houses and fixes the electromagnetic coil (5) ;
An armature (8) formed of a magnetic material and attracted to the friction surface (2a) of the drive-side rotating member (1, 2) by an electromagnetic attractive force generated by the electromagnetic coil (5);
The driven-side rotating member (12) and the armature (8) are connected to each other, and when the electromagnetic coil (5) is not energized, the armature (8) is connected to the driving-side rotating member (1, 2) an elastic coupling mechanism (9, 10, 11) for holding at a position separated from the friction surface (2a);
In the coil housing (4), it is disposed at a portion close to the friction surface (2a) of the drive side rotating member (1, 2), and melts at a predetermined temperature or more to connect to the electromagnetic coil (5). In an electromagnetic clutch provided with a thermal fuse (13) for interrupting energization,
An annular coil spool (14) is disposed in the coil housing (4), and the electromagnetic coil (5) is wound on the coil spool (14).
Of the coil spool (14), the friction surface (2a) of the drive-side rotation member (1, 2) is formed on the inner peripheral corner located on the friction surface (2a) side of the drive-side rotation member (1, 2). A stepped portion (14k) that is recessed in a direction away from
A recess (14b) is formed by the stepped portion (14k), and the thermal fuse (13) is disposed in the recess (14b) .

A drive-side rotating member (1, 2) that is formed of a magnetic body and rotates by receiving a rotational force from a rotational drive source;
A driven side rotating member (12) coupled to the rotating shaft of the driven side device;
An electromagnetic coil (5) that generates an electromagnetic attractive force when energized;
A coil housing (4) that is formed of a magnetic material and houses and fixes the electromagnetic coil (5);
An armature (8) formed of a magnetic material and attracted to the friction surface (2a) of the drive-side rotating member (1, 2) by an electromagnetic attractive force generated by the electromagnetic coil (5);
The driven-side rotating member (12) and the armature (8) are connected to each other, and when the electromagnetic coil (5) is not energized, the armature (8) is connected to the driving-side rotating member (1, 2) an elastic coupling mechanism (9, 10, 11) for holding at a position separated from the friction surface (2a);
In the coil housing (4), it is disposed at a portion close to the friction surface (2a) of the drive side rotating member (1, 2), and melts at a predetermined temperature or more to connect to the electromagnetic coil (5). In an electromagnetic clutch provided with a thermal fuse (13) for interrupting energization,
An annular coil spool (14) is disposed in the coil housing (4), and the electromagnetic coil (5) is wound on the coil spool (14).
Of the coil spool (14), the friction surface (2a) of the drive-side rotation member (1, 2) is formed on the inner peripheral corner located on the friction surface (2a) side of the drive-side rotation member (1, 2). And a stepped portion (14k) that is recessed in a direction away from the friction surface (2a) of the drive side rotating members (1, 2).
A recess (14b) is formed by the inclined surface (14a) and the stepped portion (14k), and the thermal fuse (13) is disposed in the recess (14b). Electromagnetic clutch.

A drive-side rotating member (1, 2) that is formed of a magnetic body and rotates by receiving a rotational force from a rotational drive source;
A driven side rotating member (12) coupled to the rotating shaft of the driven side device;
An electromagnetic coil (5) that generates an electromagnetic attractive force when energized;
A coil housing (4) that is formed of a magnetic material and houses and fixes the electromagnetic coil (5);
An armature (8) formed of a magnetic material and attracted to the friction surface (2a) of the drive-side rotating member (1, 2) by an electromagnetic attractive force generated by the electromagnetic coil (5);
The driven-side rotating member (12) and the armature (8) are connected to each other, and when the electromagnetic coil (5) is not energized, the armature (8) is connected to the driving-side rotating member (1, 2) an elastic coupling mechanism (9, 10, 11) that is held at a position separated from the friction surface (2a);
In the coil housing (4), it is disposed at a portion close to the friction surface (2a) of the drive side rotating member (1, 2), and melts at a predetermined temperature or more to connect to the electromagnetic coil (5). In an electromagnetic clutch provided with a thermal fuse (13) for interrupting energization,
An annular coil spool (14) is disposed in the coil housing (4), and the electromagnetic coil (5) is wound on the coil spool (14).
In this coil spool (14), a recess (14b) is formed at an inner peripheral corner located on the friction surface (2a) side of the drive side rotating member (1, 2). 14b) is provided with the thermal fuse (13),
The coil housing (4) is formed in a double cylindrical shape having a U-shaped cross section, and the friction surface of the inner cylindrical portion (4a) of the double cylindrical shape of the coil housing (4). (2a) An inclined surface (4c) that is inclined from the outer peripheral surface to the inner peripheral surface side is formed at the front end portion,
The recess (14b) is formed along the inclined surface (4c) .

The electromagnetic coil (5) is wound around an outer peripheral side region of the recess (14b) in the coil spool (14), according to any one of claims 2 to 5 . Electromagnetic clutch.

The coil spool (14) is formed of an elastic resin,
It said thermal fuse (13) and elastically held to claw into the inner peripheral corner portion (14c, 14d) are solenoid according to any one of claims 1 to 6, characterized in that are integrally molded clutch.

The coil spool (14) has notches (14g) for taking out the electromagnetic coil (5) in the vicinity of both ends of the thermal fuse (13),
The notch cut an electromagnetic coil that has been removed from (14 g) (5), according to any one of claims 1 to 7, characterized in that the electrical connection to both ends of the temperature fuse (13) Electromagnetic clutch.

Said coil spool (14) and said thermal fuse (13) is any one of claims 1 to 8, characterized in that it is fixedly held by a resin member molded in said coil housing (4) in (6) The electromagnetic clutch as described in one.